After the birth of printing books became widespread. Hence everyone throughout Europe devoted himself to the study of literature... Every year, especially since 1563, the number of writings published in every field is greater than all those produced in the past thousand years. Through them there has today been created a new theology and a new jurisprudence; the Paracelsians have created medicine anew and the Copernicans have created astronomy anew. I really believe that at last the world is alive, indeed seething, and that the stimuli of these remarkable conjunctions did not act in vain.

De Stella Nova, On the New Star (1606), Johannes Kepler Gesammelte Werke (1937- ), Vol. 1, 330-2. Quoted in N. Jardine, The Birth of History and Philosophy of Science: Kepler's A Defence of Tycho Against Ursus With Essays on its Provenance and Significance (1984), 277-8.

Among the multitude of animals which scamper, fly, burrow and swim around us, man is the only one who is not locked into his environment. His imagination, his reason, his emotional subtlety and toughness, make it possible for him not to accept the environment, but to change it. And that series of inventions, by which man from age to age has remade his environment, is a different kind of evolution—not biological, but cultural evolution. I call that brilliant sequence of cultural peaks The Ascent of Man. I use the word ascent with a precise meaning. Man is distinguished from other animals by his imaginative gifts. He makes plans, inventions, new discoveries, by putting different talents together; and his discoveries become more subtle and penetrating, as he learns to combine his talents in more complex and intimate ways. So the great discoveries of different ages and different cultures, in technique, in science, in the arts, express in their progression a richer and more intricate conjunction of human faculties, an ascending trellis of his gifts.

FAUSTUS: How many heavens or spheres are there?MEPHASTOPHILIS: Nine: the seven planets, the firmament, and the empyreal heaven.FAUSTUS: But is there not coelum igneum, et crystallinum?MEPH.: No Faustus, they be but fables.FAUSTUS: Resolve me then in this one question: Why are not conjunctions, oppositions, aspects, eclipses all at one time, but in some years we have more, in some less?MEPH.: Per inaequalem motum respectu totius.FAUSTUS: Well, I am answered. Now tell me who made the world.MEPH.: I will not.FAUSTUS: Sweet Mephastophilis, tell me.MEPH.: Move me not, Faustus.FAUSTUS: Villain, have I not bound thee to tell me any thing?MEPH.: Ay, that is not against our kingdom.This is. Thou are damn'd, think thou of hell.FAUSTUS: Think, Faustus, upon God that made the world!MEPH.: Remember this.

Explaining Napoleons remark to Gaspard Gourgaud that Engineers are more clever than artillerymen. With co-author Harold Orel, in 'How to Make Technical Writing Easy', Professional Engineer (1958), 29, 18.

The question of a possible physiological significance, in the resemblance between the action of choline esters and the effects of certain divisions of the involuntary nervous system, is one of great interest, but one for the discussion of which little evidence is available. Acetyl-choline is, of all the substances examined, the one whose action is most suggestive in this direction. The fact that its action surpasses even that of adrenaline, both in intensity and evanescence, when considered in conjunction with the fact that each of these two bases reproduces those effects of involuntary nerves which are absent from the action of the other, so that the two actions are in many directions at once complementary and antagonistic, gives plenty of scope for speculation.

There is not perhaps another object in the heavens that presents us with such a variety of extraordinary phenomena as the planet Saturn: a magnificent globe, encompassed by a stupendous double ring: attended by seven satellites: ornamented with equatorial belts: compressed at the poles: turning upon its axis: mutually eclipsing its ring and satellites, and eclipsed by them: the most distant of the rings also turning upon its axis, and the same taking place with the farthest of the satellites: all the parts of the system of Saturn occasionally reflecting light to each other: the rings and moons illuminating the nights of the Saturnian: the globe and satellites enlightening the dark parts of the rings: and the planet and rings throwing back the sun's beams upon the moons, when they are deprived of them at the time of their conjunctions. (1805)

We have no other notion of cause and effect, but that of certain objects, which have always conjoind together, and which in all past instances have been found inseparable. We cannot penetrate into the reason of the conjunction. We only observe the thing itself, and always find that from the constant conjunction the objects acquire an union in the imagination.

We need only reflect on what has been prov'd at large, that we are never sensible of any connexion betwixt causes and effects, and that 'tis only by our experience of their constant conjunction, we can arrive at any knowledge of this relation.

Unless, said I [Socrates], either philosophers become kings in our states or those whom we now call our kings and rulers take to the pursuit of' philosophy seriously and adequately, and there is a conjunction of these two things, political power and philosophic intelligence, while the motley horde of the natures who at present pursue either apart from the other are compulsorily excluded, there can be no cessation of troubles, dear Glaucon, for our states, nor, I fancy for the human race either. Nor, until this happens, will this constitution which we have been expounding in theory ever be put into practice within the limits of possibility and see the light of the sun.

In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion.
(1987) -- Carl Sagan